Field of the Invention
The present invention relates to an imprint apparatus, a method of manufacturing an article, and a supply apparatus.
Description of the Related Art
As demands for micropatterning semiconductor devices increase, a microfabrication technique of molding an uncured imprint material (resin material) on a substrate with a mold and forming a pattern of the imprint material on the substrate is attracting attention, in addition to the conventional photolithography technique. This technique is also called an imprint technique and can form a fine structure of several nm order on the substrate.
A photo-curing method is one example of the imprint technique. In an imprint apparatus which adopts the photo-curing method, first, an imprint material is supplied (applied) to a shot region (imprint region) on a substrate. Then, an uncured imprint material on the substrate is cured by irradiating it with light in a state in which the imprint material and a mold are in contact with each other, and the mold is released from the cured imprint material, thereby forming a pattern on the substrate.
A supply apparatus used when supplying an imprint material onto a substrate generally includes a tank which stores the imprint material, a discharge unit (dispenser) which discharges the imprint material, and a supply pipe which supplies the imprint material from the tank to the discharge unit. The imprint material may be contaminated by a foreign substance or a metal in a process using the imprint material. If the contaminated imprint material is used, a defective pattern is formed on the substrate, affecting a yield. To cope with this, Japanese Patent Laid-Open No. 2013-92643 proposes a technique of removing a contaminant in an imprint material with a filter. Further, Japanese Patent Laid-Open No. 2013-153063 proposes a technique of separating a contaminant in an imprint material by evaporating the imprint material once.
In this related art, however, it is impossible to prevent the contamination itself of an imprint material while it is possible to deal with an imprint material that has already been contaminated. A component of an imprint material may change by a process such as filtering or evaporation. In this case, replacement of the imprint material itself is unavoidable. It is extremely difficult to remove all contaminants that have entered an imprint material. It is difficult to supply the imprint material stably and ensure a yield unless the contamination itself of the imprint material can be prevented.
In the supply apparatus which supplies the imprint material onto the substrate, the supply pipe connects the tank which stores the imprint material and the discharge unit which discharges the imprint material, and the imprint material is discharged from the discharge unit via the supply pipe. Inside the tank, the amount of the imprint material changes by discharging the imprint material, causing a pressure fluctuation. In order to cope with the pressure fluctuation, the tank has a communication port which communicates with the exterior of the tank. If a pressure inside the tank is set at a negative pressure with respect to a pressure outside the tank, a gas outside the tank may be absorbed. As a result, particles, a metal contained in moisture, or the like present outside the tank enters inside the tank and melts into the imprint material. That is, the imprint material stored in the tank may be contaminated.